{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:02:53Z","timestamp":1789621373998,"version":"build-2803163510"},"reference-count":78,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T00:00:00Z","timestamp":1789430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Swiss-Bulgarian Research Programme (funding scheme MAPS) in the framework of the second Swiss Contribution to selected EU member states","award":["project IZ11Z0_230935 PROTON DREAMS"],"award-info":[{"award-number":["project IZ11Z0_230935 PROTON DREAMS"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Proton cranes are single-molecule photoswitches with rotor and stator parts attached, where the switching event is based on a multi-step, long-range intramolecular proton transfer within the stator. The process of intramolecular motion makes such structures prototypes for machines at a nanomolecular level with broad potential applications as novel materials, necessitating a multifaceted approach to their investigation. Theoretical design of conjugated tautomeric proton cranes, using benzothiazole as a tautomeric rotor and a variety of tautomeric OH-containing heterocycles as possible stators, has been attempted by using density functional theory calculations in various environments. The shape of the ground-state potential energy surface has been used to estimate the suitability of possible proton cranes. A previously developed and studied proton crane, named HQBT, in which the benzothiazole rotor is attached to the eighth position of the quinoline-7-ol stator, has been used as a comparative example. The results indicate that under certain conditions, cinnolin-7-ol-based proton cranes could have practical applicability in non-polar media, where the performance of HQBT is not satisfactory.<\/jats:p>","DOI":"10.3390\/mi17091084","type":"journal-article","created":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T18:23:53Z","timestamp":1789496633000},"page":"1084","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Improving Long-Range Intramolecular Proton Transfer\u2014Further Molecular Design Using the Successful Molecular Switch 8-(Benzo[d]thiazol-2-yl)quinolin-7-ol (HQBT) as a Structural Model"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2843-3698","authenticated-orcid":false,"given":"Daniela","family":"Nedeltcheva-Antonova","sequence":"first","affiliation":[{"name":"Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria"},{"name":"Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6645-8319","authenticated-orcid":false,"given":"Nikoleta","family":"Kircheva","sequence":"additional","affiliation":[{"name":"Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria"},{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"},{"name":"University Centre on Tautomeric Research and Education in Science and Technology (ERA Chair UCTREST), University of Plovdiv, 4000 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4717-8028","authenticated-orcid":false,"given":"Silvia","family":"Angelova","sequence":"additional","affiliation":[{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"},{"name":"University Centre on Tautomeric Research and Education in Science and Technology (ERA Chair UCTREST), University of Plovdiv, 4000 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0520-1517","authenticated-orcid":false,"given":"Liudmil","family":"Antonov","sequence":"additional","affiliation":[{"name":"Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria"},{"name":"Institute of Optical Materials and Technologies \u201cAcad. J. Malinowski\u201d, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Joshi, H.C., and Antonov, L. (2021). Excited-State Intramolecular Proton Transfer: A Short Introductory Review. 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